Excited-state absorption in NdAl3(BO3)4 laser crystal

We present an investigation in NdAl3(BO3)4 (NAB) crystal of the excited-state absorption (ESA) around the main laser lines (1060 and 1338 nm) by the so called excited-state excitation technique. The involved transitions are from the F3/24 level toward the G7/24+4G9/2+2K13/2 levels (1300–1400 nm range) or toward the G9/24+4G11/2+2D3/2+2K15/2 levels (1020–1100 nm range). We have performed the Judd–Ofelt analysis extended to anisotropic crystals in order to get the cross sections (cm2). In each case, the ESA peaks do not coincide with the laser emission ones, but a reduction of the effective laser emission cross section is observed at 1338 nm. Finally, the values obtained from the application of the Judd–Ofelt formalism have been used to estimate the influence of ESA in the pumping domain on the laser performance. It has been found that its contribution is not significant, indicating that NAB is an excellent candidate for efficient high-power microchip lasers emitting at 1060 and 1338 nm.